JPS6270018A - Small-sized runnerless precision injection molding equipment - Google Patents

Abstract

PURPOSE:To make the effective and proper working of various kinds of precision work pieces possible as a small-sized precision molder by a structure wherein a necessary number of tilting flow channels are bored and at the same time a necessary number of heating zones are made in a manifold in which a main flow channel is bored. CONSTITUTION:First, cavities 7 with desired shapes are made between a stationary mold 5 and a movable mold 6. At the same time, a manifold A allowing the formation of heating zones 16, the number of which coincides with the number of gates corresponding to the number of set cavities, is selected and fixed to a fixed die plate 4. Secondly, desired raw material is past through a feeding mechanism 25, a raw material plasticizing mechanism 24 and an injection plunger mechanism 26 so as to conform to the injection molding operation and raw material beads 30 are applied by the stroke action of a piston rod 27 so as to pass through a main flow channel 12 and a necessary number of tilting flow channels 15 in order to be turned into molten resin. After that, the molten resin reaches heating zones 16 and is injected through gates 9 into cavities 7 in order to be molded. Finally, the movable mold 6 is open so as to remove a molding out of the molds during the process.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] This) A#1 relates to a small runnerless precision injection molding device capable of compact and precision runnerless molding.

[Conventional technology]

With the recent remarkable development of science and technology, the demand for miniaturization and precision in various technical fields, such as electronics and biotechnology, has increased, and resin molded products have had to adapt to these demands.There is a demand for so-called small synthetic resin molding machines. has come into the limelight.

This type of molding machine improves the efficiency and precision of one operation.

From the perspective of diversifying the resins used, synthetic resin injection molding equipment that exclusively uses a sprue runner type is used, but since the sprue runner is essential, waste of the resin used cannot be avoided, and therefore The price of the molded product also has to be high.

Moreover, the molding apparatus has been simply modified from a large-sized apparatus to a smaller configuration, and there are many unnecessary components, and no new molding apparatus suitable for so-called small-sized molded products has been found.

Therefore, as a result of intensive research, the applicant has decided to apply for the patent application No. 59-2
Completed the invention of No. 16283 (filed on October 17, 1980), eliminating waste of resin with runner-less Yubu, and new configurations such as injection molten resin distribution mechanism, raw material plasticization mechanism,
We proposed a compact precision injection molding device that combines various configurations adapted to miniaturization, such as an injection plunger mechanism and a raw material supply mechanism.

[Purpose of the invention]

This invention is based on the above-mentioned patent application filed in 1973, which was developed by the present applicant.
The present invention is based on the invention of No. 9-216283, and further aims to provide a runnerless small-sized precision molding device that can effectively and appropriately process various precision processed products as a small-sized precision molding machine.

〔Example〕

Examples of this invention are shown below.

The drawings show an embodiment of a runnerless compact precision molding apparatus representing the most typical configuration according to the present invention.

First, the configuration of each figure will be explained.

1 is a movable die plate that moves back and forth along the dieper 2 by a desired mold clamping means 3; 4 is a fixed die plate; A mold 5 and a movable mold 6 are fixed together, and a cavity 7 for obtaining a desired small-sized molded product is formed by both molds 5.6.

By the way, the fixed mold 5 has a presser plate 8 that can detachably attach the manifold A to the fixed die plate 4 in the illustrated embodiment.
It is indirectly attached to the gate plate lO forming the gate 9 via a two-piece fixed back plate 11.

Next, manifold A will be explained in detail.

This manifold A has a columnar structure capable of maintaining a desired external shape, has a main flow channel 12 bored on its central axis, is equipped with a bullet-shaped torpedo 14 containing a heater 13, and -
The inclined flow path 15 is divided into the required number of holes, and a small volume heating area 16 that communicates with the gate 9 can be formed on the exit side of the inclined flow path 15. A conical tip portion 18a of a cannonball-shaped sharp heating body 18 is formed as a heat source of the heat source 16 through an opening 17 offset along a direction parallel to the main flow path 12.

By the way, in this manifold A, the number of inclined channels 15 differs depending on the number obtained by the bell-shaped operation of - times, and the number of inclined channels 15 varies depending on the case of one molded product to the case of two or more molded products. It is clear that the cavities 7 are formed symmetrically around the main channel 12 at the outer circumferential position thereof, and only the number of cavities 7 corresponding to the amount of molten resin discharged by - times of injection operations can be formed.

Therefore, the manifold A can be prepared in advance in a structure in which the number of heating regions 16 communicating with the gate 9 varies depending on the number of cavities 7, such as one or two manifolds, with the same shape and size depending on the required number of cavities 7. The entire unit can be replaced and replaced.

In this embodiment, a sharp heating element 18 is used as the heat source for the heating area 16 to adopt an internal heating method. A heater (not shown) is built in, and the molten resin in the heating area 16 can be heated while keeping it warm using an external heating method.

Furthermore, a heater 19 built into the sharp heating element 18 of the heating area 16 causes the sharp end 20 facing the gate portion to generate heat each time an injection molding operation is performed, melting the solidified resin at the gate portion and opening the gate 9. It is also possible to maintain the resin in the gate part in a semi-molten state at all times, thereby further improving the precision of the molding process.

The heating region 16 is formed as a kind of short cannonball-shaped space with the gate 9 at its apex, so a small and short sharp heating element (not shown) with a volume is disposed within this cannonball-shaped space. Of course, the long sharp heating element 18 may be replaced by the heating element 18.

Furthermore, this manifold A has a heater 13 in the main flow path 12.
A torpedo 14 with a built-in is inserted, and on the outer periphery of this torpedo 14 there are grooves 2 corresponding to the number of inclined channels 15.
1 is bored, and a sharp partition part 22 is formed on the entrance side between adjacent passage grooves 21, and the resin passage yt2 is discharged.
1 is formed, but the torpedo 14 is omitted if the resin melting and kneading action in the main channel 12 is sufficiently performed. be able to. However, the manifold A having a structure including a torpedo 14 having eight additional functions can shorten the distance of the main flow path 12, but in the case of a structure without this torpedo 14, the melting of the resin cannot be promoted, so the main flow path 12 There is no choice but to make the distance between them slightly longer.

Next, the configuration of the main channel 12 through which the molten resin can flow will be described.

In the illustrated embodiment, the main flow path 12 is formed on a straight line. That is, the rear part of the raw material plasticizing mechanism 24 is in contact with the front end of the manifold A and is integrally incorporated into the stationary die plate 4 together with the manifold A, and the front end of the raw material plasticizing mechanism 24 is an injection mechanism having the raw material supply mechanism 25. It is connected to the rear end of the plunger mechanism 26, and the stroke operation of the piston rod 27 of the injection plunger mechanism 26 is performed on the same axis as the linear main channel 12.

Moreover, the raw material plasticizing machine a24 has a cylindrical structure with a flange 28 that can be engaged with the fixed die plate 4, and is equipped with a heater 29 that can heat the main channel 12 formed at the center of the shaft to heat and melt the resin. It is constructed by wrapping it around.

Furthermore, the raw material supply mechanism 25 includes a hopper 31 that can store raw material beads 30 and a motor-driven screw-type quantitative feeder 32 that can supply a fixed amount of raw material beads 30. raw material beads 30 can be dropped and supplied into the main channel 12 of the injection plunger mechanism 26.

Furthermore, the injection plunger mechanism 26 advances the raw material beads 30 supplied into the main flow path 12 within the main flow path 12 each time an injection operation is performed by a piston rod 27 working in a piston cylinder mechanism 33 operated by hydraulic pressure or other means. At the same time, the completely melted resin is transferred to the cavity 7 through the gate 9.
It is now possible to inject it inside.

However, the structure of the raw material plasticizing mechanism 24, the raw material supply mechanism 25, and the injection plunger mechanism 26 described above is not defined, and the main point is that the main stream of the manifold A fixed in the fixed die plate 4 is Any configuration may be used as long as it can supply the necessary resin to the channel 12 in a required state such as molten or semi-molten.

The present invention will be described in detail based on the configuration shown in Section 2.

A manifold capable of forming a cavity 7 having a desired shape between a fixed mold 5 and a movable mold 6, and forming a number of heating regions 16 corresponding to the number of gates 9 corresponding to the number n of the cavities 7. Select A and fix die plate 4
Fixed to.

Then, the feed mechanism 25. Raw material plasticization mechanism 24
In response to the injection molding operation by the injection plunger mechanism 26, the raw material beads 30 are subjected to the stroke action of the piston rod 27 and pass through the main flow channel 12 through the torpedo 14. The resin reaches the heating area 16 as a molten resin, is injected into the cavity 7 through the gate 9, and is molded there.

The movable mold 6 is then opened, and the molded product is taken out in the process.

Note that during the injection molding operation, the heater 1 of the sharp heating element 18
9 is operated intermittently to cool and solidify the resin that closes the gate 9 by heating and melting the resin locally, thereby opening the gate 9 only during molding. Be sure to close gate 9 after completing the molding operation.
When closed, a small molded product with excellent moldability can be obtained.

Note that the heater 19 of the sharp heating element 18 may be kept in operation at all times to maintain the resin at the gate 9 in a molten or semi-molten state.

Note that in the above-described configuration, the gate plate IO can be composed of two members: a gate member 10a that can form the gate 9 and the heating region 16, and a stop plate 10b that locks and holds the gate member 10a.

Further, reference numeral 34 indicates a heater disposed at a necessary location, 36 indicates a cooling water hole, and 37 indicates various types of screws.

〔effect〕

As for the manifold with the main flow passages as described above, this invention allows the selection of a specific manifold that can drill the required number of inclined flow passages and form the required number of heating areas, and fixes this manifold. The plasticizing mechanism, injection mechanism, raw material supply mechanism, etc. for the raw resin that can be removably inserted into the die plate and supplied to the main channel can be of any configuration and there is no need to specify the same. It has the great effect of not being limited.

Furthermore, according to this invention, the manifold is provided with the required number of inclined flow channels, so the molten resin can be transferred smoothly and without strain, and the function of the sharp heating element facilitates the mass production of molded products with excellent moldability. It has many features such as being possible.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway side view of the overall general configuration of a typical embodiment of a runnerless compact precision injection molding apparatus according to the present invention, and FIG. 2 is a partially cutaway side view showing the configuration of the main manifold part of the same. 3 is a front view of the above manifold, FIG. 4 is a partially cutaway side view showing an example of a torpedo inserted into the manifold, and FIG. 5 is a front view of the above manifold. A...Manifold 3...Mold clamping means 4...Fixed die plate 7...
... Cavity 9 formed by fixed mold 5 and movable mold 6 ... Gate 12 ... Main channel 14 ... Torpedo 15 ... ... Inclined flow path 16 ... Heating region 18 ... Sharp heating body 18a ... Conical end portion 19 ... Heater 20 ... Sharp end 24 ... ...Raw material plasticization mechanism 25 ...Raw material supply mechanism

Claims (4)

[Claims] (1) A manifold connected to a raw material supply mechanism and an injection mechanism is detachably assembled into a fixed die plate, and
The manifold is a runner-less compact precision machine, characterized in that the main flow path is divided into one or more required number of inclined channels, and a small volume heating area communicating with a gate is provided on the outlet side of the inclined channel. Injection molding equipment. (2) The runnerless small-sized precision injection molding apparatus according to claim 1, wherein the main flow path of the manifold uses a torpedo to promote melting and kneading of the raw resin toward the divided inclined flow paths. (3) The runnerless compact precision injection molding apparatus according to claim 1, wherein the heating area is configured to expose the conical end portion of the bullet-shaped sharp heating element to keep the molten resin in the heating area warm from the inside. . (4) A patent claim in which the sharp end facing the gate of the sharp heating body is provided with a heater mechanism that can generate heat every time injection molding is performed to melt the resin at the gate, or can keep the resin at the gate half-molten at all times. The runner-less compact precision injection molding apparatus according to item 3.